Rear Roof Spoiler

[wardy18 33 1 Cars]

Under body aerodynamics also creates alot less drag than aerodynamic aids on top of the car so maybe there something to look into.

 

Sorry i forgot i even posted this one hehe

 

Yeh the rear underside of the car has a complete undertray covering from where the fuel tank used to be right up the rear bumper leaving a channel for the exhaust silencer to run throu, its been very nicely done!!

[wardy18 33 1 Cars]

I would look into the under car aerodynamics more to get ground effect. That you can do with alloy / plastic. Deeper side skirts may be required though.

Or whack one of these on it!!

 

 

that 205 spoiler is exactly what im looking for and would be perfect, i assume thats a custom build and not off the shelf!!

[wardy18 33 1 Cars]

surely the one above isnt too hard to make, the sides are easy to cut out and then a large flat section of alloy cut to shape and curved to the angle required then fitted to the sides and then fitted to the boot with lenghts of thin steel rods to rigidity?!

[brianthemagical 1]

what is the required profile of the wing? and thats a wing, not a spoiler. it lookslike a fairly low down force wing, so either the car wasn't going to get airborne, special stage or autocross maybe, or it was going reet fast.

Edited April 7, 2008 by brianthemagical

[wardy18 33 1 Cars]

i have no idea of profile, just want teh back to have more downforce for the hillclimb really and that "WING" looks perfect surely?!

[brianthemagical 1]

The profile is the hard bit and the bit you, or most people including myself, won't be able to make. It might be easy to make the shape but it is so easy to go wrong and make an inefficient aerofoil. Best bet is to buy one off the shelf/second hand, like the BTCC ones, then make it fit like you want ti to look.

[wardy18 33 1 Cars]

where can u get the BTCC ones from?!

 

i always thought that as long as it scoops up that your surely going to gain downforce and the air is being forced up the aerofoil and so pushing the back of the car down, quite a simple idea really, not sure how it gets complicated and how u can go wrong, obviously if the degree of upsweep is too much then ur going to cause too much drag and if too little you wont have any affect at all!!?!?!

 

please advise.........

[Batfink 201]

speak to Tony at Touringcarspares

[Nathan 0]

where can u get the BTCC ones from?!

 

i always thought that as long as it scoops up that your surely going to gain downforce and the air is being forced up the aerofoil and so pushing the back of the car down, quite a simple idea really, not sure how it gets complicated and how u can go wrong, obviously if the degree of upsweep is too much then ur going to cause too much drag and if too little you wont have any affect at all!!?!?!

 

please advise.........

 

Wings don’t work by acting as scoops, they work by making air travel at different speeds over the top and bottom of the wing, this then creates an area of low pressure under the wing which effectively sucks it towards the ground, the top surface actually does very little work.

[brianthemagical 1]

My first bit of advice would be to get a book on the subject, it'll help alot, especially if itstarts with the basics, even it you can't work out the downforce by sight or know the formulae, at least it'll give you an understanding of what is happening. Then you'll also know about other 'add ons' for wings, like flap and gurney strips which will help you tailor the wing for differnt circuits. Not a clue where you'd buy second hand wings personally, i still pay too much for bolts.

[wardy18 33 1 Cars]

well to be honest i cant afford to have one made and i have the materials and am pretty handy at building so how can i find out what angles etc to make it at?!

 

surely its learnable

[Rob Thomson 6]

Look up aerofoil on wikipedia to give yourself an idea of the very basics. The tear-drop shape is very important; you'll almost certainly be able to create some downforce with just an angled sheet of metal, but it'll generate far too much drag to be of any benefit. Aerofoils are very carefully shaped to generate lift whilst creating a minimal amount of drag.

 

Also, you've heard about aeroplanes stalling, right? At a certain speed the aerofoils cease to generate lift as the smooth airflow over them breaks down. Plane goes below a certain speed and then drops out of the sky like a stone. The relationship between speed and lift isn't in any way linear. Now imagine that you've bolted an aerofoil to the back of your car. Turn into a corner at high speed and you've got downforce, but as you approach the apex the speed scrubs off a bit, the aerofoil stalls, and suddenly you've got no downforce and you end up stuffed in a wall. There are so many things that could go wrong, and that's why these kinds of thing are developed on computers and in wind tunnels for hundreds of hours; they're NOT simple.

 

Personally I'd steer well clear of anything like this, but if you insist copy someone else's proven design as carefully as you can.

[wardy18 33 1 Cars]

wow never really thought it would so complicated and complex

i might just make somethin small and simple and see how i go!!

 

ill draw up a couple of small designs and see what its like!!

[brianthemagical 1]

Have a search on ebay for rear wing, theres a CF one for £30 at the mo. The mian problem with a wing like that tho is who designed it. Someone like Nathan who know what they are talking about would be a better bet to buy one off but i'm guessing there not cheap. The best bet would be to read up on it, then get to a smooth airfield and see what there like, differences in top speed, cornering ability and confidence. It might just be a case of re learning the car as you'd still be able to atleast as fast as beorfe the wing, so faster on the fast bits but the same speed on the slow bits. You'd also need to look at your suspension setup, again possibly affecting cornring ability, the max downforce may be limited by the maximum sping rate you can run. You'd also have to take into account the attitude or the car and it's affects on stuff, if you read up on areo then you'd have an idea how to load the front aswell.

Edited April 8, 2008 by brianthemagical

[brianthemagical 1]

wow never really thought it would so complicated and complex

i might just make somethin small and simple and see how i go!!

 

ill draw up a couple of small designs and see what its like!!

 

make it as wide as poss, and higher AR's produce lower L/D's. End plates are a must.

[wardy18 33 1 Cars]

make it as wide as poss, and higher AR's produce lower L/D's. End plates are a must.

 

what's AR's and L/D's?!

[Nathan 0]

what's AR's and L/D's?!

 

Lol and that's precisely why you need to do a bit of research on this subject!

 

AR is aspect ratio and is how wide a wing is comapred to its chord.

 

L/D is the lift to drag ratio.

 

If your serious about attempting to make your own wing, instead of just posting on here, I suggest looking into some books by Simon Mcbeath, although as I've already said I personally think your wasting your time, and trust me, I know how much work goes into developing a profile.....

[wardy18 33 1 Cars]

ok sound ill have a look into it and thanx for the advice, maybe one day when i have some spare funds ill come to you for a proper build!

[brianthemagical 1]

By all means have a go, just be careful when you use it, and make sure you do lots of testing to ensure it actually works and doesn't slow your top speeds down too much. I've always wanted to make my own, but haven't got round to it as of yet. Maybe one day. If you do try, report back your findings.

[wardy18 33 1 Cars]

the only trouble with guernsey is that there is no where to test these things, with you guys to just simply drive or chuck teh car on a trailer and head to a track day, no can do here!! maybe why i crashed the pug seeing as i had apsolutely no idea how it handled or drove!!

[Nathan 0]

Some information well worth digesting in another thread on a forum I frequent.

 

http://www.ten-tenths.com/forum/showthread.php?t=105501

[wardy18 33 1 Cars]

ok so this is the sort of spoiler which resulted in my naive view of making a wing of my own, this one looks so simple but in ur opinion would it actually be affective?!

[brianthemagical 1]

Looks can be deceptive. A spoiler spoils the air, so a wing could be used as a spoiler if mounted correctly, but that looks like it should be a wing and a wing is what you want. Even if you could make a wing, it's doudtful it would be as good as it could be. That pic looks like a not very got design, too short a chord length, and would probs be more useful with more camber, maybe even bigger end plates. Is it a constant thickness throughout its chord?

[wardy18 33 1 Cars]

yeh these are the things i was thinkin, ive got a pretty good idea now of whats needed so ill have a go at makin my own